Vascular access kit

ABSTRACT

Vascular access kit comprising a guidewire and a needle. The guidewire includes elastic core member ending with guidewire tip segment. Guidewire tip segment comprising widening, guidewire tip rear portion extending distally to the widening, and guidewire tip front portion extending distally from the widening. The needle comprising a beveled opening greater in length than guidewire tip front portion. Guidewire tip rear portion includes a flexing portion configured for causing localized buckling and/or bending for inclining guidewire tip front portion relative to guidewire tip rear portion, in needle beveled opening, when the core member is axially compressed.

FIELD

The present disclosure, in some embodiments thereof, relates to devices and methods for accessing a blood vessel, and more particularly, but not exclusively, to guidewires and/or vascular access kits.

BACKGROUND

The Seldinger technique is currently the preferred approach to access blood vessels, in which a needle penetrates into the vessel, and, once it is verified that the needle tip is inside the vessel, a guidewire is inserted through the needle and maneuvered to the desired place in the blood vessel, then the needle is taken out and a catheter can be positioned over the guidewire at the designated area.

Unintended perforation or dissection of the blood vessel is not an uncommon failure when using Seldinger technique. If the needle tip is positioned near the blood vessel centerline, and in an acute angle thereto, the guidewire should exit the needle tip without causing unnecessary perforation as described. However, in many cases the needle tip is too close to the opposing vessel wall, or even partly penetrated thereto, and/or the access angle of the needle relative to the blood vessel is too shallow, although the operator may obtain blood return via the inserted needle, supposedly a positive indication for a correct needle placement. However, the guidewire is forcefully pushed into the blood vessel through the needle, the tip of the guidewire can perforate the vessel wall and/or dissect vessel wall layers, especially since that guidewires are designed for sufficient pushability for allowing its advancing through the needle and the blood vessel.

The problem of unintentional penetration (e.g., perforation and/or dissection) of blood vessel wall when forming access into the blood vessel is especially noticeable in veins, in which the walls are thin and flexible, such that the operator may not sense any resistance from the needle and continue advancing the guidewire out of the vein through the unintentionally formed penetration opening. In arteries on the other hand, a situation of blood return with inability to advance the wire is more common. In such cases, the wire tip can be pushed directly against the vessel wall and even if it doesn't penetrate the vessel wall, it can cause irritation which may lead to vascular spasm commonly associated with access complications, especially vascular occlusion.

It should be noted that this Background is not intended to be an aid in determining the scope of the claimed subject matter nor be viewed as limiting the claimed subject matter to implementations that solve any or all of the disadvantages or problems presented above. The discussion of any technology, documents, or references in this Background section should not be interpreted as an admission that the material described is prior art to any of the subject matter claimed herein.

SUMMARY

The present disclosure, in some embodiments thereof, relates to devices and methods for accessing a blood vessel, and more particularly, but not exclusively, to guidewires and/or vascular access kits configured to prevent unintentional harm of blood vessel wall when forming access into a blood vessel.

In certain embodiments, there is provided a vascular access kit. The kit may include a guidewire comprising an elastic core member ending with a guidewire tip segment comprising a widening, a guidewire tip rear portion extending distally to the widening, and a guidewire tip front portion thicker than the guidewire tip rear portion extending distally from the widening; and a needle comprising a beveled opening greater in length than the guidewire tip front portion. In some embodiments, the guidewire tip rear portion includes a flexing portion configured to cause localized buckling and/or bending for inclining the guidewire tip front portion relative to the guidewire tip rear portion, in the beveled opening, when the core member is axially compressed.

In some embodiments, the core member comprises of a guidewire proximal segment extending distally to a first narrowing, a guidewire intermediate segment thinner than the guidewire proximal segment extending distally from the first narrowing to a second narrowing, and the guidewire tip segment extending distally from the second narrowing.

In some embodiments, the beveled opening is at least twice in length than the guidewire tip front portion.

In some embodiments, total length of the guidewire tip rear portion and the guidewire tip front portion is less than 10 mm.

In some embodiments, the guidewire tip rear portion is at least 2 mm in length.

In some embodiments, the guidewire tip front portion is about 1.5 mm or less in length.

In some embodiments, the guidewire tip rear portion is about 0.15 mm or less in diameter.

In some embodiments, the flexing portion is about 0.5 mm or less in length.

In some embodiments, the flexing portion is distant 5 mm or less from a distal end of the guidewire.

In some embodiments, the flexing portion is distant 1 mm or less from the guidewire tip front portion.

In some embodiments, the flexing portion has elastic properties configured for affecting self-aligning of the guidewire tip front portion with the guidewire tip rear portion upon ceasing of a moment thereon.

In some embodiments, the flexing portion has plastic properties configured for affecting residual bending stress upon ceasing of a moment thereon.

In some embodiments, the flexing portion includes a curved length along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length.

In some embodiments, the flexing portion is configured with resistance to bending and/or buckling smaller than the straight aligned portions of the core member proximally and distally adjacent to the curved length.

In some embodiments, the core member is deviated in at least one axis along the curved length.

In some embodiments, the core member forms a coil along the curved length.

In some embodiments, the flexing portion includes at least one localized lateral recess.

In some embodiments, the core member is at least partially covered with a cylindrical coiled member along the guidewire intermediate segment and the guidewire tip rear portion.

In some embodiments, the coiled member is configured with coil pitch greater along the guidewire tip rear portion than along the guidewire intermediate segment and the guidewire tip front portion.

In some embodiments, the coiled member is configured with coil pitch greater along the flexing portion rather than other portions of the guidewire tip rear portion.

In certain embodiments, there is provided a method of producing the guidewire of the kit. The method can include forming the first narrowing, the second narrowing, the guidewire tip rear portion and the widening on a pre-machined wire; and fixedly altering a straight aligned length of the guidewire tip rear portion to form the flexing portion.

In some embodiments, the forming includes grinding the pre-machined wire.

In some embodiments, the fixedly altering includes fixedly deforming the straight aligned length into a curved length, along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length.

In some embodiments, the fixedly altering includes forming at least one lateral recess or slit from the straight aligned length by way of subtractive manufacturing.

In some embodiments, the method includes connecting a cylindrical coiled member between the first narrowing and the widening of the core member.

In some embodiments, the coiled member is configured with a first coil pitch along a chosen length thereof and a second coil pitch smaller than the first coil pitch along a remainder length thereof, and the connecting includes surrounding the flexing portion with the chosen coiled member length having the first coil pitch.

In certain embodiments, there is provided a device for forming a vascular access in a blood vessel via an access needle. The device can include: an elastic core member comprising of a guidewire proximal segment extending distally to a first narrowing, a guidewire intermediate segment thinner than the guidewire proximal segment extending distally from the first narrowing to a second narrowing, a guidewire tip rear portion thinner than the guidewire intermediate segment extending distally from the second narrowing to a widening, and a guidewire tip front portion thicker than the guidewire tip rear portion extending distally from the widening; and a cylindrical coiled member extending between the first narrowing and the widening of the core member.

In some embodiments, the tip rear portion includes a flexing portion configured to affect localized buckling and/or bending for inclining the tip front portion relative to the tip rear portion when the core member is axially compressed.

In some embodiments, the coiled member is configured with a first coil pitch along a chosen length thereof surrounding the flexing portion and a second coil pitch smaller than the first coil pitch along a remainder length of the coiled member.

In some embodiments, the flexing portion includes a curved length along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length.

In certain embodiments, there is provided a method of forming a vascular access using the kit. The method can include penetrating into a blood vessel with the beveled opening; placing the guidewire tip front portion and the flexing portion in the beveled opening; pushing the guidewire tip front portion via the beveled opening against a wall of the blood vessel until generating a moment on the flexing portion sufficient to trigger local buckling and/or bending until the guidewire tip front portion is inclined relative to the guidewire tip rear portion; advancing the guidewire distally in the blood vessel; and allowing the guidewire tip front portion to flex back and/or realign with the guidewire tip rear portion.

In some embodiments, the flexing portion includes a curved length along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length, wherein the moment is generated by way of derived opposing forces acting respectively on the curved length and on the straight aligned portion of the core member proximally and/or distally adjacent to the curved length.

In some embodiments, a length of the beveled opening extends in the wall of the blood vessel. 32. The method according to claim 29, wherein the placing includes orienting the needle at an angle between 60° and 90° between the needle and the blood vessel.

All technical or/and scientific words, terms, or/and phrases, used herein have the same or similar meaning as commonly understood by one of ordinary skill in the art to which the disclosure pertains, unless otherwise specifically defined or stated herein. In case of conflict, the patent specification, including definitions, will control.

It is understood that various configurations of the subject technology will become apparent to those skilled in the art from the disclosure, wherein various configurations of the subject technology are shown and described by way of illustration. As will be realized, the subject technology is capable of other and different configurations and its several details are capable of modification in various other respects, all without departing from the scope of the subject technology. Accordingly, the summary, drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the present disclosure are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative description of some embodiments of the present disclosure. In this regard, the description taken together with the accompanying drawings make apparent to those skilled in the art how some embodiments of the present disclosure may be practiced.

FIGS. 1A-1C schematically illustrate a side view of a prior art guidewire (FIG. 1A) and cross-sectional side views the guidewire delivered into a blood vessel using a traditional Seldinger technique (FIGS. 1B-1C);

FIGS. 2A-2C schematically illustrate several views of an exemplary guidewire comprising an elastically articulatable tip portion, according to some embodiments;

FIGS. 3A-3E schematically illustrate several views representing possible scenarios in execution of a method for delivering the exemplary guidewire of FIG. 2 using an exemplary vascular access technique, according to some embodiments;

FIGS. 4A-4E schematically illustrate several views representing possible other scenarios in execution of a method for delivering the exemplary guidewire of FIG. 2 using an exemplary vascular access technique, according to some embodiments;

FIGS. 5A-5B illustrate respectively a side view of an exemplary guidewire and a cross-sectional side view of a front length thereof, according to some embodiments;

FIG. 6A illustrates an exemplary intravenous access kit comprising an exemplary needle and the guidewire shown in FIG. 5A, according to some embodiments;

FIG. 6B illustrates a cross-sectional side partial view of the intravenous kit shown in FIG. 6A in an exemplary deployment, according to some embodiments;

FIGS. 7A-7C schematically illustrate several views representing possible scenarios in execution of a method forming an intravenous access using the kit of FIG. 6A, according to some embodiments;

FIGS. 8A-8F illustrate respectively side views of distal portions of exemplary guidewire core member with different exemplary flexing portion configurations, according to some embodiments.

DETAILED DESCRIPTION

The following description and examples illustrate some exemplary implementations, embodiments, and arrangements of the disclosed invention in detail. Those of skill in the art will recognize that there are numerous variations and modifications of this invention that are encompassed by its scope. Accordingly, the description of a certain example embodiment should not be deemed to limit the scope of the present invention.

The present disclosure, in some embodiments thereof, relates to devices and methods for accessing a blood vessel, and more particularly, but not exclusively, to guidewires and/or vascular access kits configured to prevent unintentional harm (e.g., puncture) of blood vessel wall when forming access into a blood vessel. The term “guidewire” (or “guide wire”) refers to any thin member configured for facilitating a chosen route in bodily vessels for passing artifacts therealong to a target location, such as by way of passing a sheath, a cannula, a catheter or any other device over the guidewire into a cavity or vessel. In some embodiments, the term guidewire is inclusive of vascular access wires which are used in the process of forming a vascular access, optionally prior to insertion of another guidewire prescribed for routing artifacts deeper in the patient's vasculature, for example.

FIG. 1A schematically illustrates a prior art guidewire 10 having an elongated guidewire body 11, which, as in common commercially available guidewires, includes a proximal segment 12 adjoining a distal segment 13. As known in the art, the structural member forming proximal segment 12 and outer diameter thereof, may narrow at a point along the length thereof (or gradually along the entire length) to make the guidewire easier to push through bends and the like in the patient's vasculature. The distal segment 13 may be covered with a coiled member or an elastic coating or matrix. Although this design concept was developed in order to improve flexibility and maneuverability of the guidewires' distal segment when pushed inside blood vessel, while preventing buckling thereof, it has not overcome issues related to initial guidewire access into the blood vessel.

As shown in FIGS. 1B-1C, representing part of a traditional Seldinger technique, a needle 20 is first inserted into blood vessel BV until a needle tip 21 thereof is positioned adjacent to opposing blood vessel wall OBW. Then, distal segment 13 of guidewire 10 is introduced into blood vessel BV via needle 20. Although distal segment 13 is considered relatively flexible in relevant publications, the initial protruding length 15 of distal segment 13, emerging from beveled opening 22 of needle 20 adjacent tip 21, is too short to flex since that its resistance to bending is greater than blood vessel walls OBW resistance to penetration of guidewire 10 with distal end 16 thereof, as shown in FIG. 1C.

FIGS. 2A-2C schematically illustrate several views of an exemplary guidewire 30 configured for transluminal routing of artifacts in a blood vessel. As shown in FIG. 2A, guidewire 30 includes a guidewire body 31 having a guidewire distal portion that comprises an intermediate segment 35 and a tip segment 40. Guidewire intermediate segment 35 is part of distal segment of prior art guidewires described above, and it may have greater flexibility and/or elasticity relative to a guidewire proximal segment.

Tip segment 40 has a total length which is at least the length of an initial protrusion length 38 of guidewire 30 (as shown in FIG. 3B) which is prescribed for emerging through an access needle (e.g., needle 20 shown in FIG. 1B) for accessing into the blood vessel, optionally tip segment 40 is twice to three-times in length than initial protruding length 38. Tip segment 40 is optionally equal to or less than about 20 mm in total length, optionally about 10 mm or less, optionally about 5 mm or less, optionally between about 1 mm and about 4 mm in total length.

FIG. 2B is a magnified schematic illustration of a portion of tip segment 40. Tip segment 40 includes a flexing portion (e.g., point or area) 41 configured to facilitate and/or cause relative elastic articulation (shown in FIG. 2C) of adjacent front portion 42 (which extend proximally from flexing portion 41) and rear portion 43 (which extend distally from flexing portion 41) of tip segment 40, upon such a longitudinal compression. The center of the flexing portion 41 may advantageously be about 5 mm or less from the guidewire distal end 37, optionally particularly about 1 mm or less. Articulation may be in the form of bending, flexing, or pivoting around or within flexing portion 41, in one direction, several specific directions or in any direction, for example. Flexing portion 41 optionally includes at least one of a slit, a joint, an indentation, a coiled segment, or any combination thereof. Alternatively, flexing portion 41 may be conditioned differently or additionally to other portions of tip segment 40, such as by way of heat treatment and/or chemical treatment, optionally without affecting change in dimension (e.g., diameter) to the flexing portion 41. Elastic articulation means that once a flexing (articulating) force ceases, or reduces to below a certain threshold, the adjacent portions 42 and 43 and/or flexing portion 41 will recover to a no-stress or less-stressed relative positioning. Optionally, front portion 42 and rear portion 43 of tip segment 40 are normally aligned with each other, meaning that after elastic articulation and cease of flexing (articulating) force, flexing portion 41 and/or front and rear portions 42 and 43 will tend to recover elastically towards relative alignment of front portion 42 with rear portion 43 due to internal stresses generated by the recovering elastic articulation of flexing portion 41.

In some embodiments, flexing portion 41 has smaller resistance to bending than front and rear portions 42 and 43 of the tip segment 40, so that by applying bending forces or moments thereto, front portion 42 will articulate (e.g., revolve) relative to rear portion 43 which optionally remains substantially unflexed or even straighten relative to remainder of guidewire body 31. When unstressed, front and rear portions 42 and 43 of tip segment 40 are optionally normally aligned with each other or form nominal positioning angle α_(nom), therebetween which is optionally greater than 135°, optionally particularly greater than 150°, optionally particularly about 180° (i.e., front and rear portions 42 and 43 are normally straighten one with each other). The resistance to bending of the flexing portion 41 optionally increases when front and rear portions 42 and 43 shift from the nominal or unstressed relative positioning. In some embodiments, guidewire 30 is configured and/or prescribed for a minimally allowed articulation angle Amin between front and rear portions 42 and 43, when a maximally allowed force Fmax is applied, which is optionally greater than 90°; optionally between about 150° and about 90°; optionally particularly between about 135° and about 95°.

In some embodiments, the (minimal) resistance to bending of flexing portion 41—when adjacent portions 42 and 43 of tip segment 40 are aligned—is smaller than the minimal axial force sufficient to cause penetration of tip segment 40 into a blood vessel wall (such as internal wall structure of a vein) when the distal end of guidewire 30 presses against it (as shown in FIG. 3B, for example), and it gradually increases with extent of articulation. This feature can be found advantageous for assisting in prevention of unintended perforations of the host blood vessel wall such as during introduction of guidewire 30 into the blood vessel.

Optionally and additionally, when the articulation angle reaches closer to minimally allowed articulation angle α_(min), the increased resistance to bending becomes greater than resistance to buckling of the remainder nonarticulated part of tip segment 40 which comprises rear portion 43. This feature is advantageous for directing tip segment 40 anteriorly, away from the blood vessel wall and the access needle, when guidewire 30 is further pushed into the blood vessel, thereby further assisting in preventing or diminishing harm (e.g., dissection) to the blood vessel wall in proximity to the access needle, optionally even after preliminary unintentional penetration of the blood vessel wall.

In some embodiments, guidewire 30 is provided in a kit comprising at least other vascular access members such as needle 60 shown in FIG. 3A. The kit may also include a sheath and/or a dilator. Needle 60 includes a beveled opening 62 adjacent to a distal needle tip 61. Needle 60 and guidewire 30 are configured such that beveled opening 62 is similar in length to front portion 42 of tip segment 40, such that, when the guidewire body is pushed against a blood vessel wall, front portion 42 is configured to articulate about flexing portion 41 upon axial protrusion relative to distal needle tip 61. In some embodiments, beveled opening 62 is equal to or greater than front portion 42 in length. Alternatively, beveled opening 62 can be equal to or great than front portion 42 in length.

Reference is now made to FIGS. 3A-3E which schematically illustrate several views representing possible scenarios in execution of a method for delivering guidewire 30, optionally as part of an exemplary vascular access technique. In some embodiments, this vascular access technique is applicable using different types of access needles, such as needle 20. However, in some instances it may be further advantageous to apply this exemplary technique using needle 60 to maximize the outcomes of the method and/or to further diminish or prevent potential unintentional penetration of a blood vessel wall.

Needle 60 is first inserted into blood vessel BV until needle tip 61 is positioned adjacent to opposing blood vessel wall OBW (FIG. 3A). Then, guidewire 30 is introduced into needle 60 such that tip segment 40 protrudes via beveled opening 62 across needle tip 61 (FIG. 3B) while possibly causing small indentation or compression in the opposing blood vessel wall OBW, in a magnitude dependent on the pressing force applied thereto and tissue elasticity and resistance to compression. At this stage, flexing portion 41 is already protruding at least in part anteriorly (distally) from needled beveled opening 62.

FIG. 3C shows guidewire 30 after it is further pushed into blood vessel BV. As both—the longitudinal compression in tip segment 40 and resistance to compression of opposing blood vessel wall OBW— elevate, the moment acting on flexing portion 41 eventually exceeds its initial resistance to bending thereby articulating front portion 42 relative to rear portion 43, as shown.

When the longitudinal compression of guidewire body 31 against a blood vessel wall exceeds a certain threshold (optionally predetermined threshold or within a predetermined range), when the articulation angle is between nominal positioning angle α_(nom), and minimally allowed articulation angle α_(min), tip segment 40 is configured to buckle into a buckled shape, above (proximally to) flexing portion 41, relative to remainder of the guidewire body 31 (FIG. 3D). As described earlier, buckling is set to occur before the compression force generated is sufficient to penetrate into blood vessel wall OBW. Tip segment 40 is configured to buckle, optionally in a chosen or predetermined orientation, such that an apex 44 of tip segment 40 in the buckled shape points anteriorly within blood vessel BV, away from the guidewire body 31 and blood vessel wall OBW.

Furthermore, when rear portion 42 is substantially horizontal relative to blood vessel wall OBW and presses against it along most or all side length thereof, the pressure applied therethrough to blood vessel wall OBW is reduced. As such, the articulated front portion 42 is effectively serving as a stopper against further lateral progression towards opposing blood vessel wall OBW, thereby affecting anterior progression of more proximal portion of guidewire body 31 over apex 44. Upon further progress of guidewire 30 anteriorly into blood vessel BV, tip segment 40 can optionally bounce forward and regain a straighter form relative to blood vessel contour (as shown in FIG. 3E, for example).

FIGS. 4A-4E schematically illustrate several views representing possible other scenarios in execution of a method for delivering guidewire 30 using an exemplary vascular access technique. This series of scenarios relate to possible outcome and/or potential advantage of using guidewire 30 following unintentional penetration of blood vessel wall following insertion, which causes initial penetration of the guidewire into the blood vessel wall as it emerges from the access needle. Such occasions may be more prone to happen when using off the shelf needles like needle 20, unlike for example if using a dedicated kit comprising guidewire 30 and needle 60.

Needle 20 is inserted into blood vessel BV until and as shown needle tip 21 unintentionally penetrates opposing blood vessel wall OBW (FIG. 4A) and stops before an internal blood vessel wall layer IWL. Guidewire 30 is then introduced into needle 20 such that tip segment 40 protrudes via beveled opening 22 across needle tip 21 (FIG. 4B) until reaching internal wall layer IWL with flexing portion 41 located adjacent bevel opening 22. In such stage, when flexing portion 41 is free to allow articulation of front portion 42, the resistance to further advancement of needle tip segment 40 increases and causes articulation of front portion 42 relative to all other members including rear portion 43, rest of guidewire 30 and needle 20, as shown in FIG. 4C.

When the articulation angle is between nominal positioning angle α_(nom) and minimally allowed articulation angle α_(min), tip segment 40 is configured to buckle into a buckled shape, above (proximally to) flexing portion 41, relative to remainder of the guidewire body 31 (FIG. 4D). Guidewire tip segment 40 is configured such that buckling is set to occur before the reaching an axial force sufficient to penetrate further into opposing blood vessel wall OBW through inner wall layer IWL. Tip segment 40 is configured to buckle, optionally in a chosen or predetermined orientation, such that an apex 44 of tip segment 40 in the buckled shape points anteriorly within blood vessel BV, away from the guidewire body 31 and blood vessel wall OBW.

Furthermore, when rear portion 42 is substantially horizontal relative to inner wall layer IWL and presses against it along most or all side length thereof, the pressure applied therethrough to inner wall layer IWL is reduced. As such, the articulated front portion 42 is effectively serving as a stopper against further lateral progression towards opposing blood vessel wall OBW, thereby affecting anterior progression of more proximal portion of guidewire body 31 over apex 44. Upon further progress of guidewire 30 anteriorly into blood vessel BV, tip segment 40 can optionally bounce forward and regain a straighter form relative to blood vessel contour (as shown in FIG. 4E, for example).

FIGS. 5A-5B illustrate respectively side view of a guidewire 101 and a cross-sectional side view of a front length thereof. Guidewire 101 is optionally similar or identical at least in part to guidewire 30, optionally as an exemplary configuration thereof. Guidewire 101 includes an elastic core member 103, optionally made from an elastic or a super elastic material (e.g., formed of Ni—Ti alloy, for example), which extends along most or all length of the guidewire. Guidewire 101 further includes a coil member 104 covering core member 103 along part of its length. Core member 103 includes three main continuous segments which are distinguishable by functional, structural and/or dimensional characteristics: (1) a guidewire proximal segment 105 extending distally from a proximal end 106 of guidewire 101 to a first narrowing 107 of core member 103, (2) a guidewire intermediate segment 108 extending distally from first narrowing 107 to a second narrowing 109 of core member 103, and (3) a guidewire tip segment 110 extending distally from second narrowing 109 to a distal end 111 of guidewire 101.

Similar to other access guidewires configured for forming intravenous access, such as for inserting sheathes or lines, total length of guidewire 101 can be in the order of 500 mm, optionally about 450 mm, for example. Guidewire proximal segment 105 can be about 80% or more of total length of guidewire 101, optionally about 375 mm, and is indicated with a substantially constant diameter (optionally about 0.45 mm) and/or with having core member 103 uncovered with coil member 104, along most or all length thereof. Guidewire intermediate segment 108 can be in the order of 10% or 15% of guidewire 101 total length, for example, optionally about 45 mm. Guidewire intermediate segment 108 is optionally formed in a slender elongated frustum-like shape which narrows (in proximal to distal direction) continuously and/or stepwise along most or all length thereof, from first narrowing 107 to second narrowing 109. First narrowing 107 optionally may be in the order of 1%, 2% or 5% of guidewire 101 total length, and second narrowing 109 is optionally steeper than inclined length of first narrowing 107 and/or of guidewire intermediate segment 108, optionally a drop or an inclination of about 10% or more in diameter along a length of about 0.5 mm. Optionally, a short proximal widening 112 is formed between first narrowing 107 and guidewire intermediate segment 108 for example due to bonding of coil member 104 to core member 103 thereto.

Guidewire tip segment 110 is considerably shorter than the other segments and is about 2% or less (optionally in the order of 1%) of the total length of guidewire 101, optionally less than 10 mm, optionally about 5 mm or less. Guidewire tip segment 110 includes a guidewire tip rear (proximal) portion 113 and a guidewire tip front (distal) portion 119 which merge together with a local (distal) widening 114 of core member 103. Guidewire tip rear portion 113 merges to guidewire intermediate segment 108 with second narrowing 109 and it is optionally the thinnest portion of core member 103, having a constant and/or average diameter that is in the order of 30% or less of guidewire 101 maximal diameter, optionally less than 0.15 mm, optionally about mm for example, along a length of about 6 mm or less or of about 3 mm or less. Widening 114 is steep and optionally increases by more than twice in diameter (e.g., from about 0.1 mm to more than 0.25 mm for example) along a minimal length such as in the order of about 0.5 mm or 0.25 mm. Unlike first narrowing 107 and second narrowing 109 that are formed in an acute angle, widening 114 is optionally formed in an obtuse angle. Guidewire tip front portion 119 is optionally about 2 mm or less in length, comprising of a cylindrically shaped proximal section 115 and a dome-like shaped distal section 116. Proximal section 115 is optionally longer and thinner (e.g., about 0.25 mm or more in diameter and about 1.5 mm or less in length, for example) than distal section 116 thereof (which is optionally about 0.45 mm in diameter and length, for example).

Guidewire tip rear portion 113 includes a flexing portion 120 that is configured for affecting localized buckling and/or bending for causing inclination of guidewire tip front portion 119 relative to guidewire tip rear portion 113, optionally about flexing portion 120 or in proximity thereto. As will be discussed in more details with respect to FIGS. 8 , flexing portion 120 is optionally a local length or area of core member 103, along guidewire rear portion 113 or adjacently thereto, that is mechanically and/or thermally treated, such as in a material subtraction process, for producing a localized smaller resistance to buckling, flexing and/or bending and/or for affecting a geometric misalignment sufficient for causing a pivot point or area for such an inclination or articulation. In some embodiments, flexing portion 120 has elastic properties configured for affecting self-aligning of guidewire tip front portion 119 with guidewire tip rear portion 113 upon ceasing of a moment thereon. In other embodiments, flexing portion 120 has plastic properties configured for affecting residual bending stress upon ceasing of a moment thereon. Flexing portion 120 may extend along some or most length of guidewire tip rear portion 113 and is optionally about 1 mm or less, optionally about 0.5 mm or less, in length; and it is optionally 5 mm or less distant from guidewire distal end 111 and/or optionally 1 mm or less distant from guidewire tip front portion 119.

Coil member 104 is optionally cylindrical with a constant outer diameter along most or all length thereof and is configured to maintain a constant guidewire maximal outer diameter (e.g., about 0.45 mm, for example) around narrowed portions of core member 103 including around guidewire intermediate segment 108 and guidewire tip segment 110. Coil member 104 is connected with a proximal portion 117 thereof to a proximal portion of guidewire intermediate segment 108 in proximity to first narrowing 107 optionally thereby forming proximal widening 112 (shown embedded in adhesive layer, which is an exemplary connecting feature), and with a distal portion 118 thereof to proximal section 115 of guidewire tip front portion 119. In some embodiments, coiled member 104 is configured with a first coil pitch CP1 along guidewire tip rear portion 113 (optionally particularly over flexing portion 120) which is greater than a second coil pitch CP2 thereof provided along guidewire intermediate segment 108 and guidewire tip front portion 119 (and optionally also over portions of guidewire tip rear portion 113 other than flexing portion 120). In other embodiments, coil member 104 is configured with first (greater) coil pitch CP1 along other portions thereof, such as along guidewire intermediate segment 108 and/or guidewire tip front portion 119, or along most or all length thereof. In some embodiments, second coil pitch CP2 substantially equals the diameter of the coil-wire (the wire forming the coil; which may be about 0.08 mm or less, for example) such that each two adjacent coil winding is in contact or near contact, thereby resisting or preventing axial contraction and/or bending. First coil pitch CP1 is optionally greater than coil-wire diameter (e.g., more than 0.09 mm for example) thereby allowing axial contraction and/or bending and configured to facilitate inclination of guidewire tip front portion 119 relative to guidewire tip rear portion 113.

Guidewire 101 is formed by first producing separately core member 103 and coil member 104, and then connecting them as described. Core member 103 is first formed by material subtraction of a pre-machined wire (i.e., having a substantially constant diameter), such as by way of grinding (e.g., using spindle-axis grinding in which the wire is concentrically aligned to machine's spindle axis and grinded while maintaining cylindrically symmetric shape), to reach a chosen shape of core member 103, including along each one of first narrowing 107, guidewire intermediate segment 108, second narrowing 114, guidewire tip rear portion 113, widening 114, and guidewire tip front portion 119. Afterwards, a portion having a chosen length and location on guidewire tip rear portion 113 can treated to form flexing portion 120. This may include fixedly altering a straight aligned length of guidewire tip rear portion 113 to thereby form the flexing portion. Additional chemical or heat treatment may be needed. Fixedly altering the straight aligned length to form flexing portion 120 may include fixedly deforming it into a curved length, along which core member 103 is fixedly deviated laterally relatively to straight aligned portions thereof proximally and distally adjacent to the curved length. Alternatively or additionally, this process may include forming at least one lateral recess or slit from the straight aligned length by way of subtractive manufacturing, such as by using a laser source or by way of off-spindle-axis (eccentric) grinding (e.g., the grinded wire is fixated parallel and transversely to spindle axis). After forming flexing portion, coiled member 104 is sleeved over core member 103 and positioned such that guidewire tip rear portion 113 is surrounded with the length of coiled member 104 configured with first coiled pitch CP1. In some embodiments, proximal portion 117 of coiled member 104 may be connected to core member 103 by of adhesives, and distal portion 118 thereof may be welded or soldered to proximal section 115 of guidewire tip front portion 119. During or following connection of coiled member distal portion 118, the dome-like shaped distal section 116 of guidewire tip front portion 119 can be connected (e.g., welded or soldered, for example) or formed from the tip of core member 103 (e.g., grinded or forged, for example).

FIG. 6A illustrates an exemplary vascular access kit 100 comprising guidewire 101 and an exemplary needle 102. FIG. 6B illustrates a cross-sectional side view showing distal portions of guidewire 101 placed in an exemplary needle 102. Kit 100 may be a complete or partial seldinger or other vascular access or puncture kit, and may include other instruments such as a syringe, an introducer sheath and/or a dilator, and it may be equipped with one or more types or sizes of guidewire 101 and/or needle 102. Needle 102 is optionally similar or identical at least in part to needle 20 or needle 60, optionally as an exemplary configuration thereof. Needle 102 includes a hollow tube 121 sized to accommodate unhindered passage of guidewire 101 therethrough. Needle hollow tube 121 ends with a needle tip 122, configured to facilitate initial penetration through skin layers and through blood vessel walls in a live subject, and a beveled opening 123 ending at needle tip 122. The length of beveled opening 123, taken parallel to centerline of needle hollow tube 121, is greater than length of guidewire tip front portion 119 and optionally also of additional length of guidewire 101, such that in some embodiments some, most or all length of guidewire tip rear portion 113, including total length of flexing portion 120, extends along beveled opening 123, when distal ends/tips of guidewire 101 and needle 102 are juxtapositionally aligned, as shown in FIG. 6B. This way, when guidewire 101 is pushed through needle 102 against a surface common to both (i.e., both are in contact with or adjacent thereto), such as against a blood vessel wall, needle 102 does not constrain flexing portion 120 and allows localized bending and/or flexing for affecting inclination of guidewire tip front portion 119 relative to guidewire tip rear portion 113. In some embodiments, beveled opening 123 is at least twice in length than guidewire tip front portion 119, and is optionally at least 2 mm, optionally at least 4 mm, or optionally at least 6 mm long, or higher, or lower, or of any intermediate value.

FIGS. 7A-7C schematically illustrate several views representing possible scenarios in execution of a method forming an intravenous access using kit 100. As shown in FIG. 7A, needle 102 is penetrated into blood vessel BV such that beveled opening 123 is completely in the blood vessel lumen. In common practice, practitioners try to penetrate veins in most shallow angle possible, or to rotate the needle to a shallow angle immediately upon initial penetration, in order to diminish potential harm of unintentional penetration of the second (inferior) blood vessel wall by the needle tip and/or the guidewire. However, by introducing kit 100 with the tip-articulatable guidewire 101 unbound by beveled opening of needle 102, practitioners may penetrate blood vessels in less acute angles such as between 60° and 90°.

When beveled opening 123 extends at least partially within blood vessel BV, blood begins to flow proximally (upwards) via tube 121 and this can serve as indication for proper positioning in the blood vessel. However, as previously described, there can be different situations when blood is withdrawn, yet beveled opening 123 is not properly positioned for guidewire introduction, particularly known (e.g., currently available) access guidewires, which can cause harm to blood vessel wall and/or can prevent proper insertion of a catheter or sheath over the wire. In a first exemplary scenario, only a short length of beveled opening 123 has been introduced into lumen of blood vessel BV across the more proximal penetrated blood vessel wall PBW, being insufficient for passing a known guidewire therethrough into the blood vessel lumen. In this scenario, a known guidewire may be routed instead to advance through layers forming penetrated blood vessel wall PBW and to potentially cause harm thereto (e.g., unintentional dissection). In a second exemplary scenario, needle 102 has penetrated unintentionally into the more distal opposing blood vessel wall OBW, with beveled opening 123 extending at least partially in opposing blood vessel wall OBW. In this scenario, a known guidewire may be routed instead to advance across opposing blood vessel wall OBW and to potentially cause harm thereto (e.g., unintentional puncture). Guidewire 101 and kit 100 are configured with the intention to overcome such common scenarios while diminishing or preventing potential of harm to the blood vessel and providing a proper access for sheaths or catheters into the blood vessel.

In some embodiments, during or after needle penetration, optionally after blood is withdrawn and used for indicating position of bevel opening 123 in blood vessel BV, guidewire 101 can be inserted through needle 102 so that guidewire tip front portion 119 and flexing portion 120 extend along beveled opening 123 within blood vessel BV. Guidewire 101 can then be advanced distally relative to needle 102 (which can be held in place or be retracted) until guidewire tip front portion 119 is pushed against blood vessel wall (e.g., opposing wall portion OBW as shown, or against penetrated wall portion PBW) of blood vessel BV, until generating a moment on flexing portion 120 sufficiently to trigger localized inclination of guidewire tip front portion 119 relative to guidewire tip rear portion 113 (as shown in FIG. 7B, for example). The moment is optionally generated on flexing portion 120 by way of derived opposing forces acting respectively on a non-straight (e.g., curved) length within flexing portion 120 and on straight aligned portion of core member 103 proximally and/or distally adjacent to the non-straight length. As shown, by pushing guidewire tip front portion 119 against opposing blood vessel wall OBW the latter is deformed and pushed away from needle tip 122, while guidewire tip front portion 119 inclines and forms a curvature in guidewire tip rear portion 113. Due to elastic (springy) properties of guidewire tip rear portion 113, its flexing and gradually increasing curvature causes it to accumulate potential energy while pushing against opposing blood vessel wall OBW, up to a point that the stored potential energy is greater than the maximal resisting force applicable by opposing blood vessel wall OBW so that guidewire tip front portion 119 is eventually released and flexes reversely to a more elastically relaxed shape. By further advancing guidewire 101 distally in blood vessel BV, guidewire tip front portion 119 is also allowed to elastically flex back and optionally realign with guidewire tip rear portion 113, as shown in FIG. 7C for example.

FIGS. 8A-8F illustrate respectively side views of distal portions of exemplary configurations of core member 103, differentiated with exemplary configurations of flexing portion 120. In some embodiments, exemplary configurations described herein are intended for causing (affecting) localized buckling and/or bending of guidewire tip rear portion 113 along or in proximity to flexing portion 120, when core member 103 undergoes axial compression such as when pushed with forces equal to smaller than forces normally used to push access wires via access needle. Exemplary normal pushing and/or axial compression force on the guidewire sufficient to cause such buckling, bending and/or inclination in guidewire 101 are optionally lower than 2 N (newton), optionally about 1 N or less, optionally about 0.75 N or less, optionally about 0.5 N or less, optionally about 0.2 N or less, optionally about 0.1 N or less. This will allow or generate inclination of guidewire tip front portion 119 relative to guidewire tip rear portion 113 also when guidewire tip front portion 119 fully resides within beveled opening 123 of needle 102. With such configurations the aim is to avoid common failures associated with known access guidewires and kits with which such buckling, bending and/or inclination is constrained and prevented by the needle when the guidewire is pushed with normal forces, thereby increasing potential to harm blood vessel wall such as by way of unintentional puncture and/or dissection.

FIG. 8A shows guidewire 101 having a first configuration of flexing portion 120, in which flexing portion 120 includes a curved length 125 along which core member 103 is fixedly deviated laterally relatively to straight aligned portions 126 and 127 of core member 103 proximally and distally adjacent to curved length 125. In this configuration, core member 103 is deviated in a transverse axis (relative to the long axis) along curved length 120. As such, flexing portion 120 causes a local smaller resistance to buckling and/or bending along curved length 125 than along straight aligned portions 126 and 127, when core member 103 undergoes axial compression. FIG. 8B shows a similar configuration of flexing portion 120 to the previous configuration of FIG. 8A, in which length of core member 103 distal to curved length 125 is fixedly inclined at an inclination angle IA relative to length of core member 103 proximal to curved length 125. Inclination angle IA is optionally smaller than about 20°, optionally smaller than about 10°, optionally smaller than about 5°, or have any intermediate value. FIG. 8C shows guidewire 101 having a second configuration of flexing portion 120, in which flexing portion 120 forms a coil along curved length 125. In this configuration, core member 103 is deviated in several axes along curved length 120 and can compress axially under axial loads. As such, flexing portion 120 is configured with smaller resistance to buckling and/or bending along curved length 125 than along straight aligned portions 126 and 127 in any direction, when core member 103 undergoes axial compression.

FIG. 8D illustrates another configuration wherein flexing portion 120 includes at least one (in this example two) localized lateral recess 128. Recesses 128 may be formed in a process exclusive of spindle-axis (concentric) grinding, such as an off-spindle axis (eccentric) grinding. In some embodiment and as shown, the recesses are formed in different (e.g., opposite) directions with a spaced portion 129 therebetween, such that when core member 103 undergoes axial compression the differently or opposingly directed recesses 128 will affect generation of a moment about spaced portion 129 therefore cause local bending. FIG. 8E illustrates another exemplary configuration in which flexing portion 120 includes peripherally spaced slits 130 (which may be formed by way of laser cutting, for example) extending along guidewire tip rear portion 113 and splitting flexing portion 120 into four parallel smaller cores, each having a different moment of inertia for reducing local resistance to bending and/or buckling. FIG. 8F shows another exemplary configuration wherein guidewire tip front portion 119 is pivotally connected to guidewire tip rear portion 113, such that it is free to rotate about flexing portion 120 that includes a pivot connection 131 along or adjacent to widening 114.

Each of the following terms written in singular grammatical form: ‘a’, ‘an’, and ‘the’, as used herein, means ‘at least one’, or ‘one or more’. Use of the phrase ‘one or more’ herein does not alter this intended meaning of ‘a’, ‘an’, or ‘the’. Accordingly, the terms ‘a’, ‘an’, and ‘the’, as used herein, may also refer to, and encompass, a plurality of the stated entity or object, unless otherwise specifically defined or stated herein, or, unless the context clearly dictates otherwise. For example, the phrases: ‘a unit’, ‘a device’, ‘an assembly’, ‘a mechanism’, ‘a component’, ‘an element’, and ‘a step or procedure’, as used herein, may also refer to, and encompass, a plurality of units, a plurality of devices, a plurality of assemblies, a plurality of mechanisms, a plurality of components, a plurality of elements, and, a plurality of steps or procedures, respectively.

Each of the following terms: ‘includes’, ‘including’, ‘has’, ‘having’, ‘comprises’, and ‘comprising’, and, their linguistic/grammatical variants, derivatives, or/and conjugates, as used herein, means ‘including, but not limited to’, and is to be taken as specifying the stated component(s), feature(s), characteristic(s), parameter(s), integer(s), or step(s), and does not preclude addition of one or more additional component(s), feature(s), characteristic(s), parameter(s), integer(s), step(s), or groups thereof. Each of these terms is considered equivalent in meaning to the phrase ‘consisting essentially of’.

The term ‘method’, as used herein, refers to steps, procedures, manners, means, or/and techniques, for accomplishing a given task including, but not limited to, those steps, procedures, manners, means, or/and techniques, either known to, or readily developed from known steps, procedures, manners, means, or/and techniques, by practitioners in the relevant field(s) of the disclosed disclosure.

Throughout this disclosure, a numerical value of a parameter, feature, characteristic, object, or dimension, may be stated or described in terms of a numerical range format. Such a numerical range format, as used herein, illustrates implementation of some exemplary embodiments of the disclosure, and does not inflexibly limit the scope of the exemplary embodiments of the disclosure. Accordingly, a stated or described numerical range also refers to, and encompasses, all possible sub-ranges and individual numerical values (where a numerical value may be expressed as a whole, integral, or fractional number) within that stated or described numerical range. For example, a stated or described numerical range ‘from 1 to 6’ also refers to, and encompasses, all possible sub-ranges, such as ‘from 1 to 3’, ‘from 1 to 4’, ‘from 1 to 5’, ‘from 2 to 4’, ‘from 2 to 6’, ‘from 3 to 6’, etc., and individual numerical values, such as ‘1’, ‘1.3’, ‘2’, ‘2.8’, ‘3’, ‘3.5’, ‘4’, ‘4.6’, ‘5’, ‘5.2’, and ‘6’, within the stated or described numerical range of ‘from 1 to 6’. This applies regardless of the numerical breadth, extent, or size, of the stated or described numerical range.

Moreover, for stating or describing a numerical range, the phrase ‘in a range of between about a first numerical value and about a second numerical value’, is considered equivalent to, and meaning the same as, the phrase ‘in a range of from about a first numerical value to about a second numerical value’, and, thus, the two equivalently meaning phrases may be used interchangeably. For example, for stating or describing the numerical range of room temperature, the phrase ‘room temperature refers to a temperature in a range of between about 20° C. and about 25° C.’, and is considered equivalent to, and meaning the same as, the phrase ‘room temperature refers to a temperature in a range of from about 20° C. to about 25° C.’.

The term ‘about’, as used herein, refers to ±10% of the stated numerical value.

It is to be fully understood that certain aspects, characteristics, and features, of the disclosure, which are, for clarity, illustratively described and presented in the context or format of a plurality of separate embodiments, may also be illustratively described and presented in any suitable combination or sub-combination in the context or format of a single embodiment. Conversely, various aspects, characteristics, and features, of the disclosure which are illustratively described and presented in combination or sub-combination in the context or format of a single embodiment, may also be illustratively described and presented in the context or format of a plurality of separate embodiments.

Although the disclosure has been illustratively described and presented by way of specific exemplary embodiments, and examples thereof, it is evident that many alternatives, modifications, or/and variations, thereof, will be apparent to those skilled in the art. Accordingly, it is intended that all such alternatives, modifications, or/and variations, fall within the spirit of, and are encompassed by, the broad scope of the appended claims.

All publications, patents, and or/and patent applications, cited or referred to in this disclosure are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent, or/and patent application, was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this specification shall not be construed or understood as an admission that such reference represents or corresponds to prior art of the present disclosure. To the extent that section headings are used, they should not be construed as necessarily limiting.

When describing an absolute value of a characteristic or property of a thing or act described herein, the terms “substantial,” “substantially,” “essentially,” “approximately,” and/or other terms or phrases of degree may be used without the specific recitation of a numerical range. When applied to a characteristic or property of a thing or act described herein, these terms refer to a range of the characteristic or property that is consistent with providing a desired function associated with that characteristic or property.

Various modifications to the implementations described in this disclosure can be readily apparent to those skilled in the art, and generic principles defined herein can be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the claims, the principles and the novel features disclosed herein. The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

Certain features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features can be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination can be directed to a sub-combination or variation of a sub-combination.

The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims. 

1. A vascular access guidewire, comprising: comprising an elastic core member ending with a guidewire tip segment comprising a widening, a guidewire tip rear portion extending distally to the widening, and a guidewire tip front portion thicker than the guidewire tip rear portion extending distally from the widening; wherein the guidewire tip rear portion includes a flexing portion configured to cause localized buckling and/or bending for inclining the guidewire tip front portion relative to the guidewire tip rear portion, in the beveled opening, when the core member is axially compressed; wherein the flexing portion includes a curved length along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length.
 2. The guidewire according to claim 1, wherein the core member comprises of a guidewire proximal segment extending distally to a first narrowing, a guidewire intermediate segment thinner than the guidewire proximal segment extending distally from the first narrowing to a second narrowing, and the guidewire tip segment extending distally from the second narrowing. 3.-13. (canceled)
 14. The guidewire according to claim 1, wherein the flexing portion is configured with resistance to bending and/or buckling smaller than the straight aligned portions of the core member proximally and distally adjacent to the curved length.
 15. The guidewire according to claim 1, wherein the core member is deviated in at least one axis along the curved length.
 16. The guidewire according to claim 1, wherein the core member forms a coil along the curved length.
 17. The guidewire according to claim 1, wherein the flexing portion includes at least one localized lateral recess. 18.-20. (canceled)
 21. A method of producing the guidewire according to claim 2, comprising: forming the first narrowing, the second narrowing, the guidewire tip rear portion and the widening on a pre-machined wire; and fixedly altering a straight aligned length of the guidewire tip rear portion to form the flexing portion.
 22. The method according to claim 21, wherein the forming includes grinding the pre-machined wire.
 23. The method according to claim 21, wherein the fixedly altering includes fixedly deforming the straight aligned length into a curved length, along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length.
 24. The method according to claim 21, wherein the fixedly altering includes forming at least one lateral recess or slit from the straight aligned length by way of subtractive manufacturing.
 25. The method according to claim 21, comprising connecting a cylindrical coiled member between the first narrowing and the widening of the core member.
 26. The method according to claim 25, wherein the coiled member is configured with a first coil pitch along a chosen length thereof and a second coil pitch smaller than the first coil pitch along a remainder length thereof, and the connecting includes surrounding the flexing portion with the chosen coiled member length having the first coil pitch.
 27. A device for forming a vascular access in a blood vessel via an access needle, comprising: an elastic core member comprising of a guidewire proximal segment extending distally to a first narrowing, a guidewire intermediate segment thinner than the guidewire proximal segment extending distally from the first narrowing to a second narrowing, a guidewire tip rear portion thinner than the guidewire intermediate segment extending distally from the second narrowing to a widening, and a guidewire tip front portion thicker than the guidewire tip rear portion extending distally from the widening; and a cylindrical coiled member extending between the first narrowing and the widening of the core member; wherein the tip rear portion includes a flexing portion configured to affect localized buckling and/or bending for inclining the tip front portion relative to the tip rear portion when the core member is axially compressed; wherein the coiled member is configured with a first coil pitch along a chosen length thereof surrounding the flexing portion and a second coil pitch smaller than the first coil pitch along a remainder length of the coiled member.
 28. The device according to claim 27, wherein the flexing portion includes a curved length along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length.
 29. A method of forming a vascular access using the guidewire according to claim 1, the method comprising: penetrating into a blood vessel with a beveled opening of an access needle; placing the guidewire tip front portion and the flexing portion in the beveled opening; pushing the guidewire tip front portion via the beveled opening against a wall of the blood vessel until generating a moment on the flexing portion sufficient to trigger local buckling and/or bending until the guidewire tip front portion is inclined relative to the guidewire tip rear portion; advancing the guidewire distally in the blood vessel; and allowing the guidewire tip front portion to flex back and/or realign with the guidewire tip rear portion.
 30. The method according to claim 29, wherein the flexing portion includes a curved length along which the core member is fixedly deviated laterally relatively to straight aligned portions of the core member proximally and distally adjacent to the curved length, wherein the moment is generated by way of derived opposing forces acting respectively on the curved length and on the straight aligned portion of the core member proximally and/or distally adjacent to the curved length.
 31. The method according to claim 29, wherein a length of the beveled opening extends in the wall of the blood vessel.
 32. The method according to claim 29, wherein the placing includes orienting the needle at an angle between 60° and 90° between the needle and the blood vessel.
 33. A method of producing the guidewire according to claim 1, comprising: forming the guidewire tip rear portion, the guidewire tip front portion, and/or the widening on a pre-machined wire; and fixedly altering a straight aligned length of the guidewire tip rear portion to form the flexing portion.
 34. A vascular access kit, comprising the guidewire according to claim 1 and a needle comprising a beveled opening greater in length than the guidewire tip front portion. 